This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. To evaluate the efficacy of Xolair , compared to placebo, when administered to inner-city children and adolescents with moderate-to-severe allergic asthma receiving standardized specialist care and basic asthma education. Anti-IgE, omalizumab, as a new and novel treatment for asthma represents an opportunity to answer current concerns regarding adverse effects of ICS use in children, treatment of more severe asthma in children allowing lower dose ICS, reducing exacerbations, and, improving the quality of life in relation to asthma. All of this is particularly relevant to children living in urban communities where increased asthma morbidity is documented. Adherence to prescribed medications required to be administered daily is low in inner-city children. Anti-IgE is an injection therapy and has the benefit of being an administered and observed therapy. The Inner-City Asthma Consortium will conduct a randomized, double-blind, placebo-controlled, parallel group efficacy and safety trial designed to compare 250 inner-city children and adolescents age 6-20 years old with moderate-to-severe allergic asthma receiving standardized specialist care, including basic asthma education, with 250 similar children and adolescents receiving comparable standardized specialist care and treatment with Xolair . Over a 60-week period, participants will receive subcutaneous injections of Xolair or placebo every two or four weeks, along with standardized specialist care. After the double-blind, placebo-controlled treatment period, all consenting participants will be enrolled in an open-label 24 week treatment period with Xolair . A final post-treatment evaluation will be conducted approximately 16 weeks following the final injection. ICATA has been designed as a "real-world" trial of the effectiveness of Xolair in urban children and adolescents with moderate-to-severe allergic asthma. The study results may change the paradigm of management for persistent allergic asthma that could be particularly beneficial for children living in the inner-city where there appear to be unique characteristics, such as allergen exposure and poor adherence to therapy. The ICATA Weight Study will be conducted in parallel with the main study (Appendix 1), and aims to examine the relationship between body weight/composition, asthma morbidity, and biomarkers of inflammation. These data may provide important covariate information for the main analyses. The primary endpoint will be the maximum number of asthma symptom days defined as the highest value among three variables: number of days with wheezing, tightness in the chest, or cough;number of nights with disturbed sleep due to asthma;and number of days on which the participant had to slow down or discontinue play/physical activities over a two-week period.